Atomic Theory Timeline

By pratvipatel
  • 400 BCE

    Democritus

    Democritus
    Birth-460 BC
    Death- 370 BC
    He proposed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped.
    Fun Fact- He travel as far east as India and as far south as Ethiopia.

  • John Dalton

    John Dalton
    Birth- September 5,1766
    Death- July 27,1844
    John Dalton proposed that all matter is made up of extremely small particles. He also proposed that atoms of the same element have identical size, mass, and other properties. Atoms of different elements don't have these same properties.
    Fun Fact- He was born into a Quaker family.

  • Sir JJ John Thomson

    Sir JJ John Thomson
    Birth- December 18,1856
    Death- August 30,1940
    JJ Thomson proposed a experiment with cathode ray tube showing that all atoms contain tiny negatively charged particles or electrons.
    Fun Fact- JJ Thomson works aside of Niels Bohr

  • Ernest Baron Rutherford

    Ernest Baron Rutherford
    Birth- August 30, 1871
    Death- October 19,1937
    Ernest Rutherford proposed that the Atom has a dense positively charged core calling it the nucleus. he also said that all the mass in the atom revolves around the nucleus like planets revolve around the sun.
    Fun Fact- He was the first person to win the Nobel Prize from Oceania.

  • Niels Henrik David Bohr

    Niels Henrik David Bohr
    Birth- October 7, 1885
    Death- November 18, 1962
    Niels Bohr proposed that electrons orbit the nucleus in orbits that have a set size and energy.
    Fun Fact- An element was named after him.

  • Robert Andrew Millikan

    Robert Andrew Millikan
    Birth- March 22,1868
    Death- December 19,1953
    Robert Millikan proved electrons exist. He made an oil experiment proving the existence.
    Fun Fact- He enjoyed tennis and golf

  • Erwin Schrodinger

    Erwin Schrodinger
    Birth- August 12,1887
    Death- January 4,1967
    Erwin Schrodinger calculated the energy level in from electrons in a atom.
    Fun Fact- He earned a PhD at the age of 23

  • Werner Heisenberg

    Werner Heisenberg
    Birth- December 5,1901
    Death- February 1,1976
    Werner Heisenberg formulated a type of quantum mechanics based on matrices.
    Fun fact he grew up in Würzburg, Germany.

  • Sir James Chadwick

    Sir James Chadwick
    Born- October 20,1891
    Death- July 24,1974
    James Chadwick proved the existence of neutron.
    Fun Fact- When he moved to New Mexico during the Manhattan Project, he was given the alias James Chaffee, for security purposes.